Iran passed another night without US airstrikes on July 26, as Washington paused a war nearing its fifth month and reports emerged that concerns over dwindling munitions were restraining plans for further escalation.

Iran's army warned on Sunday that the Middle East war would widen if the United States chose to press ahead with attacks on the Islamic republic, ahead of the visit of Israeli Prime Minister Benjamin Netanyahu to Washington.

"I believe that if the Americans once again fall for the Zionists' deception, or move in line with them, and insist on continuing the war, particularly through air strikes, geographically this will expand further," army spokesman Mohammad Akraminia told state television.

He said the war had already expanded to the Bab al-Mandab Strait at the entrance of the Red Sea, referencing the recent military flare-up between Yemen's Iran-backed Houthi rebels and Saudi Arabia.

"The scope of our operations now encompasses the entire region, from US bases in Jordan to the countries along the Persian Gulf," he said.